AT - Pipe Umbrella System

The AT - Pipe Umbrella System is a pre-support measure used in weak ground conditions in conventional as well as mechanized Tunneling. Pipe umbrella pipes increase the stability in the working area by transferring loads in the longitudinal direction and decrease excavation induced deformations. The system increases safety in the working area. Beside this standard usage, the system is often applied to increase stability in portal sections and for the re-excavation of collapsed sections in underground construction. Another application area is ground improvement and waterproofing in combination with all tunnel construction methods.

Fields of Application

Advances in weak ground and ground conditions prone to subsidence

Advances in alpine fault zones

Advances in sediments or talus

Portal sections

Advances in frequently changing ground conditions

Re-excavation of collapsed drifts or tunnels

Urban Tunneling

Main Advantages

Installation with conventional drill jumbos

Execution of pipe umbrella drilling with on-site personnel

Simple and robust system components

Fast self-drilling installation

Smallest possible stress relaxation due to an immediate support of the borehole wall during installation

Accurate installation due to a minimized annular gap

Length of pipe umbrella pipes can be adapted to constricted space

Different pipe coupling types available to suit different project requirements